Rifampicin-loaded polymethylmethacrylate: is it possible to preserve mechanical properties and setting time?

Abstract

Two-stage exchange with antibiotic-loaded bone cement spacers remains the gold standard for chronic periprosthetic infection. Rifampicin is highly efficient on stationary-phase staphylococci in biofilm; however, its addition to PMMA to manufacture spacers prevents polymerization and reduces mechanical properties. Isolation of rifampicin during polymerization by microencapsulation, which could allow manufacturing rifampicin-loaded bone cement maintaining elution and mechanical properties. Microcapsules of rifampicin with alginate, polyhydroxybutyrate (PHBV), ethylcellulose and stearic acid were synthesized. Rifampicin elution to phosphate buffer was measured by UV-visible spectroscopy. Alginate and PHBV microcapsules were added to bone cement CMW®1 and elution, compression, bending, hardness and setting time tests were performed. Antimicrobial activity was assessed by disk diffusion test with S.aureus ATCC®29213TM. Repeated measures ANOVA and Bonferroni post-hoc test using SPSS version 22.0 were performed, considering a p